The present invention relates to a printer, copier, facsimile transceiver or similar image recording apparatus and, more particularly, an image recording apparatus having various modular components each being constructed into a unit and operatively connected together by external arrangements.
Image recording apparatuses such as copiers, printers and facsimile transceivers are implemented with various kinds of image forming principles or systems. Typical of image forming systems are an electrophotographic system, a thermal printing system, and an ink jet printing system. Further, each of such systems forms black-and-white images and color images by using exclusive apparatuses. It has been customary to produce apparatuses for implementing the various image forming systems independently of one another. For example, when both of the ink jet printing system and the thermal printing system are desired, at least two exclusive printers have to be prepared. When a person having a black-and-white printer desires color printing, the person has to purchase a color printer or to replace the black-and-white printer with a printer having black-and-white and color printing capabilities. This not only increases the user's expenditure but also requires the manufacturers to produced various kinds of printers at all times.
An image recording apparatus may have a part thereof, e.g., a developing device or an image forming device including a developing device and a photoconductive element constructed into a replaceable unit, as disclosed in Japanese Patent Publication No. 20832/1989 and Japanese patent Laid-Open Publication Nos. 99861/1984 and 273057/1989 by way of example. This is successful in promoting easy replacement of expendables and replacement of analog and digital image forming systems. However, since such a replaceable unit scheme does not change the physical appearance of the apparatus, the functions available with the apparatus cannot be extended beyond a certain limit. In addition, since the change in the internal arrangement of the apparatus cannot be observed from the outside, an undesired kind of printing is apt to occur.